"A belief, however necessary it may be for the preservation of a species, has nothing to do with truth. The falseness of a judgment is not for us necessarily an objection to a judgment. The question is to what extent it is life-promoting, life-preserving, species preserving, perhaps even species cultivating. To recognize untruth as a condition of life--that certainly means resisting accustomed value feelings in a dangerous way; and a philosophy that risks this would by that token alone place itself beyond good and evil."

Source: Friedrich Nietzsche (2010). “The Gay Science: With a Prelude in Rhymes and an Appendix of Songs”, p.84, Vintage